The present invention relates to a remotely actuated switches and control devices, e.g., for turning an electric appliance on or off, or for changing its speed or other operating condition.
Among present available remote operators, and typically found in households, are infrared units. These remote operators are mainly used in connection with video or audio electronics for controlling selection, volume, and other functions. Because of the variety of the functions that need to be controlled, the infrared unit employs a code modulation technique, with a sequence of blinking signals to control the respective functions. The infrared signal is generated by an IR LED in a hand-held remote unit, and is received by a sensor installed in the television, VCR, stereo, CD player, or the like. Every specific function of the infrared operator requires a separate, distinctive code. Different electronics units require a different set of codes for the same function, because the same hand held remote operator is going to emit light that is visible to all the controlled devices at the same time. Because the LED emits light over a broad area, the light disperses rapidly. This means that the unit will function even if not pointed at the receiver, and can function from IR signals that bounce off walls or ceilings. However, this limits the range of the remote operator to only about 20 or 30 feet.
Another form of remote operator currently in use is a radio-frequency (RF) operator. This kind of remote operation is especially useful when the controlled device is not on a line of sight, or is located inside a different space or building. This system also requires specific codes and often requires specific frequencies for different functions. These RF units are also susceptible to RF interference, and jamming. A high volume of RF traffic, as well as high amounts of electrical activity, for example in industrial spaces, can render these remote operators rather unreliable. Moreover, because the remote operator emits more or less omnidirectionally, the range can also be rather limited.
Acoustic remote operators are also in use, but have found limited practical applicability. An example of this is a xe2x80x9cclap-handsxe2x80x9d switch. These operators are subject to false activation, and are also of limited value where reliability is needed. Other remote operators can employ a presence detection system.
A need exists for a remote operator which is highly reliable and simple to use, and which has a strictly local character. There is also a need for a remote operator of general or universal operation, and which does not require special codes for each controlled unit. It is also desired for the remote operator to be free from problems that may arise from RF interference or other interference, and can be used for even simple xe2x80x9conxe2x80x9dxe2x80x94xe2x80x9coffxe2x80x9d applications for devices in close proximity to one another. There is a need for such a remote operator that can operate at some distance from the controlled device.
It is an object to provide a remote operator that is simple and reliable, and which avoids the drawbacks of the prior art.
It is another object to provide remote operator that can be employed in a variety of noisy and RF rich environments, and which is not subject to false actuation due to stray radiation or from high levels of ambient radiation.
In accordance with an aspect of this invention, the remote operator can take the form of a laser-actuated photo switch, in which a hand held laser sweeps past an active or sensitive area on the unit to cause the unit to change states, e.g., between xe2x80x9conxe2x80x9d and xe2x80x9coff.xe2x80x9d In more advanced embodiments, pointing the laser at the photosensitive position of the unit can cause it to increment (between dim and bright, fast and slow, soft and loud, etc.), or the unit can turn the device on for a timed period, after which it automatically shuts off. It is envisioned that the hand held laser produce a narrow beam of laser light at a single predetermined wavelength. However, in some applications, it may be useful to employ a laser beam of two or more discrete wavelengths
In any of several preferred embodiments, the remote operator permits hands-off switching of an electric load device in response to a sweep of a laser beam over a sensor portion of the remote operator. An optical sensor element is sensitive to a predetermined wavelength characteristic of the laser beam, and a relay device (which can be an electromechanical relay or an electronic switching element) follows the optical sensor element and is actuated by it. There is wiring connecting the optical sensor element and the relay device with a source of electrical power (AC line power, or battery power, for example), and also wiring connecting the relay with load device. A dark filter or other optical filter can be disposed over the optical sensor element for passing only light at the laser""s characteristic wavelength. This ensures that the ambient light or other reflected or direct light will not cause false switching.
A monostable, bistable or other multivibrator unit can be employed to effect toggling or a timed on (or timed off) operation.
The remote operator can be integrated into the housing or body of the load device, e.g., into a ceiling fan, wall switch, table lamp, or any other device in need of remote controlled operation.
The above and many other advantages and features of this invention will become apparent from the ensuing description of selected preferred embodiments of the invention.